Department of Physics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
Laboratoire Charles Coulomb, University of Montpellierr, CNRS, Montpellier, 34095, France.
Nano Lett. 2022 May 25;22(10):3889-3896. doi: 10.1021/acs.nanolett.1c05037. Epub 2022 May 4.
Nanoindentation based on atomic force microscopy (AFM) can measure the elasticity of biomaterials and cells with high spatial resolution and sensitivity, but relating the data to quantitative mechanical properties depends on information on the local contact, which is unclear in most cases. Here, we demonstrate nonlocal deformation sensing on biorelevant soft matters upon AFM indentation by using nitrogen-vacancy centers in nanodiamonds, providing data for studying both the elasticity and capillarity without requiring detailed knowledge about the local contact. Using fixed HeLa cells for demonstration, we show that the apparent elastic moduli of the cells would have been overestimated if the capillarity was not considered. In addition, we observe that both the elastic moduli and the surface tensions are reduced after depolymerization of the actin cytoskeleton in cells. This work demonstrates that the nanodiamond sensing of nonlocal deformation with nanometer precision is particularly suitable for studying mechanics of soft biorelevant materials.
基于原子力显微镜的纳米压痕技术能够以高空间分辨率和灵敏度测量生物材料和细胞的弹性，但要将数据与定量力学性能相关联，则取决于局部接触的信息，而在大多数情况下，这一点并不清楚。在这里，我们通过使用纳米金刚石中的氮空位中心，在原子力显微镜压痕时对生物相关软物质进行非局部变形传感，从而无需详细了解局部接触，即可提供用于研究弹性和毛细现象的数据。通过使用固定的 HeLa 细胞进行演示，我们表明如果不考虑毛细现象，细胞的表观弹性模量将会被高估。此外，我们观察到，在细胞中的肌动蛋白细胞骨架解聚后，弹性模量和表面张力都降低了。这项工作表明，纳米金刚石对非局部变形的纳米精度传感特别适合于研究软生物相关材料的力学。
